A linear guide (linear motion guide) includes a guide rail, a slider block, and a rolling element. A circulation path of the rolling element is formed between the guide rail and the slider block. The guide rail and the slider block relatively operate (move) by circulation of the rolling element within the circulation path.
The rolling element accommodated in the circulation path is separated from the slider block when the guide rail is removed (pulled) from the slider block. When the rolling element is separated from the slider block, treatment at the time of assembly or repair is complicated and difficult. For this reason, the slider block is provided with a rolling element retainer for preventing separation of the rolling element.